Optical device, transmitter, and transceiver

Abstract

An optical device includes: a substrate having a first surface and a second surface opposite to each other; an optical modulating unit provided in the substrate, at the first surface, the optical modulating unit having a plurality of electrodes for modulating an optical signal; a plurality of vias extending in a thickness direction of the substrate and connected to a plurality of ground electrodes included in the plurality of electrodes; and a second-surface electrode provided at the second surface of the substrate and connected to the plurality of vias.

What is claimed is: 
     
         1 . An optical device, comprising:
 a substrate having a first surface and a second surface opposite to each other;   an optical modulating unit provided in the substrate, at the first surface, the optical modulating unit having a plurality of electrodes for modulating an optical signal;   a plurality of vias extending in a thickness direction of the substrate and connected to a plurality of ground electrodes included in the plurality of electrodes; and   a second-surface electrode provided at the second surface of the substrate and connected to the plurality of vias.   
     
     
         2 . The optical device according to  claim 1 , further comprising an optical waveguide provided in the substrate, at the first surface, wherein
 the optical modulating unit has an electro-optic constant that is higher than an electro-optic constant of the optical waveguide.   
     
     
         3 . The optical device according to  claim 1 , wherein a material of the substrate is silicon, silica, or quartz. 
     
     
         4 . The optical device according to  claim 1 , wherein the optical modulating unit has a Mach-Zehnder type structure. 
     
     
         5 . The optical device according to  claim 1 , wherein the optical modulating unit has a GSGSG configuration in which the plurality of electrodes corresponds to a differential signal for driving, in the GSGSG configuration, “G” indicating one of the plurality of ground electrodes and “S” indicating a signal electrode of the plurality of electrodes. 
     
     
         6 . The optical device according to  claim 1 , wherein the optical modulating unit has a GSG configuration in which the plurality of electrodes corresponds to a single output signal for driving, in the GSG configuration, “G” indicating one of the plurality of ground electrodes and “S” indicating a signal electrode of the plurality of electrodes. 
     
     
         7 . The optical device according to  claim 1 , further comprising a plurality of substrates, wherein
 the substrate is a first substrate of the plurality of substrates,   the plurality of substrates includes a second substrate different from the first substrate, the second substrate having a first surface and a second surface opposite to each other, the first surface of the second substrate facing the second surface of the first substrate, a ground electrode being provided on the first surface of the second substrate, and   the ground electrode on the first surface of the second substrate and one of the plurality of vias are connected by a bump.   
     
     
         8 . The optical device according to  claim 1 , wherein the second-surface electrode is disposed in the substrate, between the first surface and the second surface of the substrate. 
     
     
         9 . The optical device according to  claim 1 , wherein the plurality electrodes includes a segmented electrode. 
     
     
         10 . The optical device according to  claim 1 , wherein,
 a thickness of the substrate is decreased to a predetermined thickness, and   the substrate is mounted on an interposer.   
     
     
         11 . A transmitter, comprising:
 a substrate having a first surface and a second surface opposite to each other;   an optical modulator provided on the substrate; and   an optical device related to an optical transmission function, wherein   the optical modulator has:
 an optical modulating unit provided in the substrate, at the first surface, the optical modulating unit having a plurality electrodes for modulating an optical signal, 
 a plurality of vias extending in a thickness direction of the substrate and connected to a plurality of ground electrodes included in the plurality electrodes, and 
 a second-surface electrode provided at the second surface of the substrate and connected to the plurality of vias. 
   
     
     
         12 . A transceiver, comprising:
 a substrate having a first surface and a second surface opposite to each other;   an optical modulator provided on the substrate; and   an optical device related to an optical transceiver function, wherein   the optical modulator has:
 an optical modulating unit provided in the substrate, at the first surface, the optical modulating unit having a plurality electrodes for modulating an optical signal, 
 a plurality of vias extending in a thickness direction of the substrate and connected to a plurality of ground electrodes included in the plurality electrodes, and 
 a second-surface electrode provided at the second surface of the substrate and connected to the plurality of vias.